Good to see this forum. I have a specific scenario on the Clause 7.3 Design and development applied to Website design.
In general, the project methodology captures all stages i.e. includes planning, requirement gathering, building, internal testing and external user testing, sign-off, deployment and support transition. Above stages are aligned with the requirements of clause 7.3 of ISO 9001:2008. A Microsoft project is used to showcase these stages.
Now in some situations, the project being small, Internal testing is not always feasible or requirement hence no time slot available for this task in the Microsoft project server. Accordingly to me, this is major non-conformity as " In the planning stage the requirement of Internal testing not required is not identified neither there is any proof nor evidence in the particular stage.

In my opinion it is not a major non-conformity. It seems that section 7.3 is implemented in your QMS, so the issue of, in some cases, not fulfilling all of 7.3 would only qualify as a minor. But of course, that's just my humble opinion.

Might be helpful to know what your role is. Internal auditor, external auditor, client, stakeholder, benevolent onlooker, ...? If you're an auditor, you can write it up as a finding, certainly. Whether or not you call it major would be your call but should be assessed against the risk.

The company, though, should look at their planning process and allow for these 'small' projects that don't require the level of focus / documentation that larger ones do.